While talking with a friend in a bar a few weeks ago, he made the joke "if we aren't supposed to drink and drive, why do bars have such large parking lots?" and it got this reply from me "if drinking and driving is such a problem, why don't we have random operation pull-overs at all exits or random bars?". This simple statement ignited a very colorful and humorous discussion with about thirty people throughout the night, and most of the understandable and respectable comments were to the effect of "I would call a cab, not drink, or have someone else drive".
Seriously if I was still a drinker and I knew there was a chance that the P.D. had set up a check point when I was in the bar, and I knew that it could and would happen at any bar, I either wouldn't drink in the first place or would have a D.D.
Now my obvious question is why don't we do this?